3 SES Codes. Help
It threw code: P0174 a month ago
Fuel Trim Bank Two Condition. The ECM has detected a rich or lean air/fuel ratio condition on engine bank two.
Probable Causes:
-Fuel condition or MAF sensor fault
-Failed HO2S21
-Ignition misfire
-Fuel injector problem
Then last week threw: P0507
IAC circuit condition or idle speed higher/lower than expected. The ECM has detected that the IAC counts are higher or lower then expected, the engine speed is not in it's expected range.
Probable Causes:
-Vacuum leak on engine
-Dirty throttle body
-IAC motor defective
-Poor electrical connection to the IAC valve
It also threw P0171 when they scanned it.
So first we cleaned the throttle body and cleaned all the oil out. Then it made a loud whistling noise when we started it, so we looked for leaks in the hoses. Found one in the PCV system betwen the valve and intake manifold, replaced the hose and valve. That took care of the whistling and choppy idle and low idle. The light is still on not sure what codes it will be throwing now, any ideas as to what to check next? We're bringing it to my mechanic tomorrow morning so they can scan it and check out what they come up with. This **** is frustrating, but ran without any problems for the 4 years that I have owned it so I can't complain.
You may have found/repaired the vacuum leak but did you clear the codes?
The light wont immediately go out after a repair on it's own.
It wont self clear the light with out numerous problem free drive cycles.



